1. Field of the Invention
The present invention relates to a method for producing hydrogen by using magnesium scrap and an apparatus thereof, and particularly to a method for producing hydrogen by spontaneous chemical reaction without consumption of extra energy.
2. Related Art
In recent years, fossil sources are excessively exploited and utilized, taking a risk of energy shortage and environmental pollution. Consequently, hydrogen-based energy recycle gradually takes the place of the fossil-based carbon energy recycle. Although hydrogen exists in the earth's crust under particular conditions, it is too little in quantity to be exploited or recycled. As a result, production of hydrogen has to rely on artificial technology.
Nowadays, industrial production of hydrogen mostly employs fossil fuels (petroleum, savageness, coal and etc.) to generate hydrogen by different processes, for example steam reforming, partial oxidation and gasification. In view of human ecology, these hydrogen production processes using fossil fuels generate a lot of carbon dioxide (which brings about earth's greenhouse effect) and other contaminants. Hydrogen production method eliminating secondary pollution, instead of using fossil fuels, is economical and environment-protective, and therefore meets the tendency of hydrogen source development.
Electrolysis of water is a relatively easy and clean way for producing hydrogen. However, it consumes a great deal of power, requiring high production cost, and correspondingly, cannot accord with long-term environment protection. Saving power is needed in hydrogen production to obtain actual environment-protective effect. Currently, a new method for producing hydrogen attracts people's attention, where NaBH4 is immersed in alkaline solution, and then hydrogen is generated by using catalyst, such as Ru, Pt, etc. The hydrogen is readily and quickly produced by this method. But NaBH4 has to be abstracted from borate ore. Abstraction of 1 kilogram NaBH4 costs about 80 dollars, and borate ore is mostly collected in several countries, for instance the United States and Turkey. So this method is not economical, either.
In addition, metal scrap is used to recycle hydrogen. As an example, aluminum scrap is grinded to powder and acquires high chemical vigor. The aluminum is put into the sodium hydroxide solution, generating hydrogen. It's reported in documentations that magnesium powder serves as source for producing hydrogen. However, in these methods, these metals as source for producing hydrogen, namely aluminum powder and magnesium powder, need to be firstly grinded to tiny powder, which often takes extra energy and elevates cost. Additionally, the metal powder has to be stored rather careful to avoid powder blast.
On the other hand, some research involves that recycled aluminum can serve as material for producing hydrogen. However plastic coated on recycled aluminum can has to be cleaned out by vitriolic solution, which also produces industrial waste liquid.
Thus, a method which is high efficient and takes less energy without secondary pollution is desired.